This powerful first in a new thriller series from Swedish sisters Grebe and Träff introduces a delightfully flawed heroine, Dr. Siri Bergman, a psychologist who sleeps with the lights on. Riddled with fears since her husband’s death in a diving accident, Siri lives alone in an isolated cottage in the Swedish countryside. When Siri finds the lifeless body of one of her patients, the fragile but manipulative Sara Matteus, floating in the lake near her cottage, she fears she’ll be the next victim. After receiving a threatening note, Siri enlists the help of a detective, Markus Stenberg. Together they sift through her patient files and delve into the lives of her friends, and soon everyone in her inner circle becomes a suspect. Scenes from Siri’s therapy sessions with her patients add a note of credibility and immediacy to her predicament. The action moves swiftly to a surprising climax. Agent: Anna Frankl and Joakim Hansson, the Nordin Agency. (July)